Thu·Dec 28, 2017Thursday·December 28, 2017

1. 01*

   Understanding the properties of $\Xi (1690)$ and $\Xi (2120)$

   K. P. Khemchandani🇧🇷 · A. Martínez Torres🇧🇷 · A. Hosaka🇯🇵 · H. Nagahiro🇯🇵 · F. S. Navarra🇧🇷 · M. Nielsen🇧🇷

   In this manuscript we discuss the results of our recent study on $\Xi$ resonances. We have studied meson-baryon interaction with strangeness $-2$ by solving scattering equations in a coupled channel approach and found that the dynamics gives rise to the development of two poles in the complex plane close to the real axis. The corresponding narrow states have isospin half and spin half in one case and spin 3/2 in the other case. We find that the properties of the isospin and spin 1/2 state are strikingly similar to $\Xi (1690)$, while the state with spin 3/2 can be related to $\Xi (2120)$. We find that our results on $\Xi (1690)$ are in good agreement with the data available from the BELLE and BABAR Collaborations. Our formalism consists of treating pseudoscalar-baryon and vector-baryon channels on an equal footing. Since the thresholds of such channels are distributed over a relatively larger energy range, we obtain all interaction kernels needed to solve the Bethe-Salpeter equation without resorting to any nonrelativistic approximation even though the amplitudes are calculated at low energies.

   hep-phPoS(2018)·1 citation
2. 02*

   Model independent evaluation of the Wilson coefficient of the Weinberg operator in QCD

   Tomohiro Abe🇯🇵 · Junji Hisano🇯🇵 · Ryo Nagai🇯🇵

   We derive a Wilson coefficient of a CP-violating purely gluonic dimension-6 operator called the Weinberg operator ($GG\tilde{G}$) generated by a scalar and two fermions at the two-loop level. We do not specify the representation of SU(3)${}_c$ for the scalar and the fermions, and thus our result can be applied to a variety of models beyond the standard model. We estimate the nucleon EDMs induced by the Weinberg operator in some examples and discuss the importance of measuring EDMs. It is found that future measurements of the EDMs can probe physics at higher energy scale beyond the reach of collider experiments.

   hep-phJHEP(2018)·19 citations
3. 03*

   TOP 2017: Theoretical Summary

   Kirill Melnikov🇩🇪

   I summarize the theory talks presented at the TOP 2017 conference.

   hep-ph1 citation
4. 04*

   A simple and natural interpretations of the DAMPE cosmic-ray electron/positron spectrum within two sigma deviations

   Jia-Shu Niu🇨🇳 · Tianjun Li🇨🇳 · Fang-Zhou Xu🇨🇳

   The DArk Matter Particle Explorer (DAMPE) experiment has recently announced the first results for the measurement of total electron plus positron fluxes between 25 GeV and 4.6 TeV. A spectral break at about 0.9 TeV and a tentative peak excess around 1.4 TeV have been found. However, it is very difficult to reproduce both the peak signal and the smooth background including spectral break simultaneously. We point out that the numbers of events in the two energy ranges (bins) close to the 1.4 TeV excess have $1\sigma$ deficits. With the basic physics principles such as simplicity and naturalness, we consider the $-2\sigma$, $+2\sigma$, and $-1\sigma$ deviations due to statistical fluctuations for the 1229.3~GeV bin, 1411.4~GeV bin, and 1620.5~GeV bin. Interestingly, we show that all the DAMPE data can be explained consistently via both the continuous distributed pulsar and dark matter interpretations, which have ${\chi }^2\simeq 17.2$ and ${\chi }^2\simeq 13.9$ (for all the 38 points in DAMPE electron/positron spectrum with 3 of them revised), respectively. These results are different from the previous analyses by neglecting the 1.4 TeV excess. At the same time, we do a similar global fitting on the newly released CALET lepton data, which could also be interpreted by such configurations. Moreover, we present a $U(1{)}_D$ dark matter model with Breit-Wigner mechanism, which can provide the proper dark matter annihilation cross section and escape the CMB constraint. Furthermore, we suggest a few ways to test our proposal.

   hep-phastro-ph.HEEPJC(2019)·24 citations
5. 05*

   Dark Matter Signals at the LHC from a 3HDM

   A. Cordero🇲🇽 · J. Hernandez-Sanchez🇲🇽 · V. Keus🇫🇮 · S.F. King🇬🇧 · S. Moretti🇬🇧 · D. Rojas🇲🇽 · D. Sokolowska🇵🇱

   We analyse new signals of Dark Matter (DM) at the Large Hadron Collider (LHC) in a 3-Higgs Doublet Model (3HDM) where only one doublet acquires a Vacuum Expectation Value (VEV), preserving a parity $Z_2$. The other two doublets are \textit{inert} and do not develop a VEV, leading to a {\it dark scalar sector} controlled by $Z_2$, with the lightest CP-even dark scalar $H_1$ being the DM candidate. This leads to the loop induced decay of the next-to-lightest scalar, $H_2\to H_{1}f\bar{f}$ ($f=u,d,c,s,b,e,\mu ,\tau$), mediated by both dark CP-odd and charged scalars. This is a smoking-gun signal of the 3HDM since it is not allowed in the 2HDM with one inert doublet and is expected to be important when $H_2$ and $H_1$ are close in mass. In practice, this signature can be observed in the cascade decay of the SM-like Higgs boson, $h\to H_1{H}_2\to H_1{H}_{1}f\bar{f}$ into two DM particles and di-leptons/di-jets, where $h$ is produced from either gluon-gluon Fusion (ggF) or Vector Boson Fusion (VBF). However, this signal competes with the tree-level channel $q\bar{q}\to H_1{H}_1{Z}^{\ast }\to H_1{H}_{1}f\bar{f}$. We devise some benchmarks, compliant with collider, DM and cosmological data, for which the interplay between these modes is discussed. In particular, we show that the resulting detector signature, $\text{Et}f\bar{f}$, with invariant mass of $f\bar{f}$ much smaller than $m_Z$, can potentially be extracted already during Run 2 and 3. For example, the $H_2\to H_1{\gamma }^{\ast }$ and ${\gamma }^{\ast }\to e^{+}{e}^{-}$ case will give a spectacular QED mono-shower signal.

   hep-phJHEP(2018)·38 citations
6. 06*

   Singlet scalar and 2HDM extensions of the Standard Model: CP-violation and constraints from $(g-2{)}_{\mu }$ and $e$EDM

   Venus Keus🇫🇮 · Niko Koivunen🇫🇮 · Kimmo Tuominen🇫🇮

   We study popular scalar extensions of the Standard Model, namely the singlet extension, the 2-Higgs doublet model (2HDM) and its extension by a singlet scalar. We focus on the contributions of the added scalars to the anomalous magnetic moment of the muon, $(g-2{)}_{\mu }$ in the presence of CP-violation, and the electric dipole moment of the electron ($e$EDM) in these models. In the absence of CP-violation, CP-even and CP-odd scalars contribute with an opposite sign to the anomalous magnetic moment of the muon and as a result these models generally require very light scalars to explain the observed discrepancy in $(g-2{)}_{\mu }$. We study the effect of CP-violation on the anomalous magnetic moment of the muon and its compatibility with the $e$EDM constraints. We show that given the current status of the global set of constraints applied on all values of $\cot \beta$, in the CP-violating scalar extensions, there exist no viable parameter space in agreement with both $a_{\mu }$ and $e$EDM bounds.

   hep-phJHEP(2018)·38 citations
7. 07*

   Torsion Limits From $t\bar{t}$ Production at the LHC

   Fernando Marroquim · Fernando de Andrade🇧🇷 · Maria A. B. do Vale🇧🇷 · Andre Nepomuceno🇧🇷

   Torsion models constitute a well known class of extended quantum gravity models. In this work, one investigates the phenomenological consequences of a torsion field interacting with top quarks at the LHC. A torsion field could appear as a new heavy state characterized by its mass and couplings to fermions. This new state would form a resonance decaying into a top anti-top pair. The latest ATLAS $t\bar{t}$ production results from LHC 13 TeV data are used to set limits on torsion parameters. The integrated luminosity needed to observe torsion resonance at the next LHC upgrades are also evaluated, considering different values for the torsion mass and its couplings to Standard Model fermions. Finally, prospects for torsion exclusion at the future LHC phases II and III are obtained using fast detector simulations.

   hep-phPRD(2018)·3 citations
8. 08*

   Unruh thermal hadronization and the cosmological constant

   Antonia M. Frassino🇨🇭 · Marcus Bleicher🇩🇪 · Robert B. Mann🇨🇦

   We use black holes with a negative cosmological constant to investigate aspects of the freeze-out temperature for hadron production in high energy heavy-ion collisions. The two black hole solutions present in the anti-de Sitter geometry have different mass and are compared to the data showing that the small black hole solution is in good agreement. This is a new feature in the literature since the small black hole in general relativity has different thermodynamic behavior from that of the large black hole solution. We find that the inclusion of the cosmological constant (which can be interpreted as the plasma pressure) leads to a lowering of the temperature of the freeze-out curve as a function of the baryochemical potential, improving the description previously suggested by Castorina, Kharzeev, and Satz.

   ↳ hep-thgr-qchep-phPLB(2018)·2 citations
9. 09*

   Smarr Integral Formula of D-dimensional Stationary Spacetimes in Einstein-Æther-Maxwell Theroy

   Fei-hung Ho🇨🇳 · Shao-Jun Zhang🇨🇳 · Hai-Shan Liu🇨🇳 · Anzhong Wang🇺🇸

   Using the Wald formalism, we investigate the thermodynamics of charged black holes in D-dimensional stationary spacetimes with or without rotations in Einstein-æther-Maxwell theory. In particular, assuming the existence of a scaling symmetry of the action, we obtain the Smarr integral formula, which can be applied to both Killing and universal horizons. When restricted to 4-dimensional spherically symmetric spacetimes, previous results obtained by a different method are re-derived.

   ↳ gr-qcastro-ph.GAhep-phhep-thPLB(2018)·8 citations
10. 10*

    An analysis of the Lattice QCD spectra for $D_{s0}^{\ast }(2317)$ and $D_{s1}^{\ast }(2460)$

    A. Martinez Torres🇧🇷 · E. Oset🇪🇸 · S. Prelovsek🇸🇮 · A. Ramos🇪🇸

    In this talk I present the results obtained using effective field theories in a finite volume from a reanalysis of lattice data on the $K{D}^{(\ast )}$ systems, where bound states of $KD$ and $K{D}^{\ast }$ are found and associated with the states $D_{s0}^{\ast }(2317)$ and $D_{s1}^{\ast }(2460)$, respectively. We confirm the presence of such states on the lattice data and determine the weight of the $KD$ channel in the wave function of $D_{s0}^{\ast }(2317)$ and that of $K{D}^{\ast }$ in the wave function of $D_{s1}^{\ast }(2460)$. Our results indicate a large meson-meson component in both cases.

    ↳ hep-lathep-phPoS(2018)·6 citations
11. 11*

    Fast simulation of the CEPC detector with Delphes

    Cheng Chen🇨🇳 · Xin Mo🇨🇳 · Michele Selvaggi🇨🇭 · Qiang Li🇨🇳 · Gang Li🇨🇳 · Manqi Ruan🇨🇳 · Xinchou Lou🇨🇳

    Fast simulation tools are highly appreciated in particle physics phenomenology studies, especially in the exploration of the physics potential of future experimental facilities. The Circular Electron Positron Collider is a proposed Higgs and Z factory that can precisely measure the Higgs boson properties and the electroweak precision observables. A fast-simulation toolkit dedicated to the CEPC detector has been developed using Delphes. The comparison shows that this fast simulation tool is highly consistent with the full simulation, on a set of benchmark distributions. Therefore, we recommend this fast simulation toolkit for CEPC phenomenological investigations.

    ↳ hep-exhep-ph16 citations
12. 12*

    CP symmetry and thermal effects on Dirac bi-spinor spin-parity local correlations

    A. E. Bernardini🇧🇷 · V. A. S. V. Bittencourt🇮🇹 · M. Blasone🇮🇹

    Intrinsic quantum correlations supported by the $SU(2)\otimes SU(2)$ structure of the Dirac equation used to describe particle/antiparticle states, optical ion traps and bilayer graphene are investigated and connected to the description of local properties of Dirac bi-spinors. For quantum states driven by Dirac-like Hamiltonians, quantum entanglement and geometric discord between spin and parity degrees of freedom - sometimes mapped into equivalent low energy internal degrees of freedom - are obtained. Such \textit{spin-parity} quantum correlations and the corresponding nonlocal intrinsic structures of bi-spinor fermionic states can be classified in order to relate quantum observables to the (non)local behavior of these correlations. It is shown that free particle mixed states do not violate the Clauser-Horne-Shymony-Holt inequality: the correlations in such mixed bi-spinors, although quantum, can be reproduced by a suitable local hidden variable model. Additionally, the effects due to a non-minimal coupling to a homogeneous magnetic field, and to the inclusion of thermal effects are evaluated, and quantum correlations of associated quantum mixtures and of the thermal states are all quantified.The above-mentioned correlation quantifiers are then used to measure the influence of CP transformations on \textit{spin-parity} quantum correlations, and our results show that quantum entanglement is invariant under CP transformations, although the geometric discord is highly sensitive to the CP symmetry.

    ↳ quant-phhep-phAnnals Phys.(2018)·2 citations
13. 13*

    Searches for 3.5 keV Absorption Features in Cluster AGN Spectra

    Joseph P. Conlon🇬🇧

    We investigate possible evidence for a spectral dip around 3.5 keV in central cluster AGNs, motivated by previous results for archival Chandra observations of the Perseus cluster and the general interest in novel spectral features around 3.5 keV that may arise from dark matter physics. We use two deep Chandra observations of the Perseus and Virgo clusters that have recently been made public. In both cases, mild improvements in the fit ($\Delta {\chi }^2=4.2$ and $\Delta {\chi }^2=2.5$) are found by including such a dip at 3.5 keV into the spectrum. A comparable result ($\Delta {\chi }^2=6.5$) is found re-analysing archival on-axis Chandra ACIS-S observations of the centre of the Perseus cluster.

    ↳ astro-ph.HEhep-phMNRAS(2018)·3 citations
14. 14*

    Bootstrapping pentagon functions

    Dmitry Chicherin🇩🇪 · Johannes Henn🇩🇪 · Vladimir Mitev🇩🇪

    In PRL 116 (2016) no.6, 062001, the space of planar pentagon functions that describes all two-loop on-shell five-particle scattering amplitudes was introduced. In the present paper we present a natural extension of this space to non-planar pentagon functions. This provides the basis for our pentagon bootstrap program. We classify the relevant functions up to weight four, which is relevant for two-loop scattering amplitudes. We constrain the first entry of the symbol of the functions using information on branch cuts. Drawing on an analogy from the planar case, we introduce a conjectural second-entry condition on the symbol. We then show that the information on the function space, when complemented with some additional insights, can be used to efficiently bootstrap individual Feynman integrals. The extra information is read off of Mellin-Barnes representations of the integrals, either by evaluating simple asymptotic limits, or by taking discontinuities in the kinematic variables. We use this method to evaluate the symbols of two non-trivial non-planar five-particle integrals, up to and including the finite part.

    ↳ hep-thhep-phJHEP(2018)·116 citations
15. 15*

    The ghost-gluon vertex in the presence of the Gribov horizon

    B. W. Mintz🇧🇷 · L. F. Palhares🇧🇷 · S. P. Sorella🇧🇷 · A. D. Pereira🇩🇪

    We consider Yang-Mills theories quantized in the Landau gauge in the presence of the Gribov horizon via the refined Gribov Zwanziger (RGZ) framework. As the restriction of the gauge path integral to the Gribov region is taken into account, the resulting gauge field propagators display a nontrivial infrared behavior, being very close to the ones observed in lattice gauge field theory simulations. In this work, we explore a higher correlation function in the Refined Gribov-Zwanziger theory: the ghost-gluon interaction vertex, at one-loop level. We show explicit compatibility with kinematical constraints, as required by the Ward identities of the theory, and obtain analytical expressions in the limit of vanishing gluon momentum. We find that the RGZ results are nontrivial in the infrared regime, being compatible with lattice YM simulations in both SU(2) and SU(3), as well as with solutions from Schwinger-Dyson equations in different truncation schemes, Functional Renormalization Group analysis, and the RG-improved Curci-Ferrari model.

    ↳ hep-thhep-lathep-phPRD(2018)·32 citations
16. 16*

    Dark energy, scalar singlet dark matter and the Higgs portal

    Ricardo G. Landim🇧🇷

    One of the simplest extensions of the Standard Model (SM) comprises the inclusion of a massive real scalar field, neutral under the SM gauge groups, to be a dark matter candidate. The addition of a dimension-six term into the potential of the scalar dark matter enables the appearance of a false vacuum that describes the cosmic acceleration. We show that the running of the singlet self-interaction and the Higgs portal coupling differs from the standard scalar singlet dark matter model. If we maintain a positive quartic coupling, it is also possible to describe the accelerated expansion of the Universe through a false vacuum with the addition of a dimension-eight interaction term. In this case, where the potential remains bounded from below at low energies, the false vacuum decay is highly suppressed.

    ↳ astro-ph.COgr-qchep-phMod.Phys.Lett.A(2018)·8 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.